Product price displayed on rack is different from the amount scanned at the counter. Wtd?

There’s a 24/7 grocery store on my way home from work and almost weekly ako namimili don. Just this midnight, I bought a few things na I carefully selected because my budget is only ₱200.

The price shown for 555 Sardines - Green variant for 425g is ₱56 and for the spicy one (red), ₱57. It’s the cheapest among all the sardines within the same weight. I got three green so that’s ₱168. I bought snacks totaling below ₱50 para sure akong hindi aabot ng 200 lahat ng binili ko. Pag-dating sa counter, I was preparing my two ₱100 bills tas bigla sabi ni kuya kulang. Kakita ko sa POS, ₱212. I was too tired from work to check yung resibo but I kept it naman.

Kauwi ko, I checked the receipt and I saw that ₱62 yung registered price nung sardines, ₱6 higher than the amount displayed sa rack. I’ve read somewhere that there’s something I can do abt this but I can’t remember if sa PH ba nangyari yun. Also, the grocery store doesn’t have barcode stickers on each item. Yung price din na naka-display, manually written on cardboard tas ni-tape nalang sa rack.

May pwede ba ‘kong gawin dito?